Cisco IPSec Unspecified IKE Traffic Denial Of Service Vulnerabilities

Risk

High

Date Discovered

November 14, 2005

Description

Various Cisco IOS, PIX Firewall, Firewall Services Module (FWSM), VPN 3000 Series Concentrator, and MDS Series SanOS releases are prone to denial of service attacks. These issues are due to security flaws in Cisco's IPSec implementation. The vulnerabilities may be triggered by malformed IKE traffic.
Successful attacks will cause most affected devices to restart. For Cisco MDS Series devices, this is limited to causing the IKE process to restart.

Monitor network traffic to the device for signs of anomalous or suspicious activity. Such activity may be logged by deployed network intrusion detection systems or may be evident in the logs generated by affected devices.

Cisco has released an advisory detailing fixes for affected devices. Please see the attached advisory for further information.
Cisco has made revision 1.4 of their advisory available. Updates to this advisory modify the affected packages list as well as changes to the 'Additional Details' section. Please see the referenced advisory for further information.
Cisco has made revision 1.5 of their advisory available. Updates to this advisory modify the affected packages list as well as changes to the 'Additional Details' section. Please see the referenced advisory for further information.
Cisco has made revision 1.6 of their advisory available. Some additional details for Cisco IOS were added. Please see the referenced advisory for further information.
Cisco has made revision 1.7 of their advisory available. The release date for fixed software version 12.3(11)T9 has been altered to be 27 Dec. 2005. Please see the referenced advisory for further information.

Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.

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